【单选题】冰箱除味剂的主要成分是活性炭,活性炭是黑色粉末或颗粒。下列说法不正确的是( )
B.
用果壳、木材等炭化制备活性炭的过程只包含物理变化
D.
活性炭具有很强的吸附性,是因为活性炭具有疏松多孔的结构
【简答题】常用活性炭颗粒有 ______ 、 ________ 、 ______ 三种形式
【简答题】为了探究“水的净化”过程,某实验小组从某河中取了水样,观察到:A、水样呈黄色,有异味 B、水样浑浊,有固体小颗粒.现对水样进行如下处理: (1)向水样中加入明矾[化学式为KAl(SO 2 ) 2 ]搅拌溶解,静置一段时间后,进行______(填操作名称),除去固体小颗粒,再向滤液中加入活性炭,利用其______性除去水样中的颜色和异味; (2)将水样通过一定操作得到蒸馏水,把下列物质分别加入适量...
【单选题】Listen to the following passage and answer Q uestions 11-12 . Which statement is NOT true according to the passage? ( )
A.
Everything we run into has an impact on our brain.
B.
We can research our brain with the help of technology.
C.
Research on sample of adolescents found that there is small and negative association between technology use and well being.
D.
Nowadays we’re very clear how technology influences our brain.
【单选题】采用对抗贮存法养护中药时,可与冬虫夏草同贮的是()。
【单选题】Which statement is true about disagreement?
A.
No position is presented in a disagreement.
B.
No persuasion in a disagreement.
【简答题】下列物质都可用于水质的净化或杀菌消毒. (1)明矾和活性炭:向水中加入明矾搅拌溶解,静置一段时间后,进行______(填操作名称),从而除去固体小颗粒;再向所得的澄清液中加入活性炭,利用其 ______除去水中的颜色和异味. (2)高铁酸钾(化学式K 2 FeO 4 )集氧化、凝聚、杀菌功能于一体,目前被广泛应用于自来水净化处理领域.高铁酸钾中铁元素的化合价为______. (3)臭氧(化学式O ...
【单选题】Which statement is NOT correct about the jump seat?
A.
It is a single jump seat.
B.
Cabin attendant’s work station is around here.
C.
It contains a lap belt and shoulder harness.
D.
It is located near the door.
【单选题】用于空气过滤的介质主要有纤维状物和颗粒状物,其中最为常用、价格又低廉的过滤介质为()。
【单选题】采用对抗贮存法养护中药时,可与蛤蚧同贮的是( )。